Marine Ecosystems Research Department - jamstec japan agency ...

JAMSTEC 2002 Annual Report
Frontier Research System for Extremophiles
Fig. 6 Alvinocaris longirostris in the DEEP AQUARIUM. Eggs can
be confirmed in the abdomen.
Fig. 7 Tissue culture cell (KMHA-1) of Simenchelys parasiticus.
pression and decompression while observing the
organism's condition. At atmospheric pressure,
Alvinocaris longirostris spawned after one week.
(iii) Establishment of tissue culture techniques
Tissue culture techniques are necessary for observing
deep-sea organisms at the tissue cell level. Primary
culture was carried out on a cell from the tissue of the
captured benthic multicellular organisms Simenchelys
parasiticus. The captured Simenchelys parasiticus was
gradually decompressed to atmospheric pressure.
After slicing the fin tissue, swarmer cell was observed
in the medium culture. The fibroblast cell of
Simenchelys parasiticus was cultivated by using L-
medium with % FBS (Fig.). Optimal temperature
was ˚C, and doubling time of cell was .h - . We
observed cell growth under the high-pressure environment,
and pressure tolerance. New tissue culture cell
(KMHA-) is cultivated and kept in frozen storage in
the laboratory.
3.2. Behaviors of biological substances and colloidal
dispersions in supercritical water
(a) Microscopic observations of biological substances
in supercritical water
We have developed an optical microscope equipped
with a high-temperature and pressure cell, and studied
behaviors of various biological substances in nearcritical
and supercritical water. The samples studied so far
include polysaccharides, proteins, microorganisms,
inorganic materials, and synthetic polymers. Although
optical microscopy helps to grasp the behavior of the
system quickly, it is rather difficult to perform quantitative
study by microscopic observations alone. This
year, we attempted to extract quantitative information
from the images by applying computer-based image
analysis.
Analysis was performed on the images obtained for
several cellulose samples. These samples have the same
molecular weight, but differ in crystallinity and crystalline
form. In addition, regenerated cellulose is highly
porous and has significantly larger surface area than the
crystalline samples. We attempted to evaluate the effect
of these factors on the dissolution temperature. The
sample was dispersed in water at the concentration of
. wt%, introduced into the high-temperature and
pressure cell, and pressurized to MPa at room temperature.
The sample was then heated to ˚C, and the
behavior of the sample during heating was observed
and video-taped. Images were then transferred to a
computer, and subjected to image analysis.
Dissolution of cellulose led to an increase of transmittance.
By calculating the relative transmittance
of the images taken at different temperatures, semiquantitative
comparison of the dissolution temperature
of different cellulose samples could be made.
Comparison revealed that cellulose with higher crys-
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